Rollup merge of #121146 - compiler-errors:ignore-diverging-arms, r=estebank

Only point out non-diverging arms for match suggestions

Fixes #121144

There is no reason to point at diverging arms, which will always coerce to whatever is the match block's evaluated type.

This also removes the suggestion from #106601, since as I pointed out in rust-lang/rust#72634 (comment) the added suggestion is not firing in the right cases, but instead only when one of the match arms already *actually* evaluates to `()`.

r? estebank

Author: GuillaumeGomez